From Piranesi to Canaletto, eighteenth century painters were fascinated by the recently excavated and partly reconstructed ruins of the Roman Forum. The temple had a special place in the history of the forum. In Republican times it served as a meeting place for the Senate; from the middle of the second century BC the bases of the columns were the speaker’s platform. But most crucially, in the imperial period the temple housed the office for weights and measures, the standards for all calculation and exchange. The destruction of the forum was thus also the destruction of the institutions and the tools that could measure and quantify this very destruction. In Piranesi’s etchings, the ruins of the forum stand in a large field where farmers engage in plowing. In Canaletto’s painting a group of “grand tourists” appear to be studying three of its surviving temple columns. The field is not the rubble of buildings damaged in faraway wars, and it is not discussed in the safety of a pristine new forum, but what is debated is quite literally the ruins of the forum in the ruins of the forum.